COLUMBUS, Ohio (AP) — Environmental regulators in Ohio want to set limits on the pollution in streams that feeds toxic algae on lakes in the state including Lake Erie, where the blooms threaten drinking water used by millions, northern Ohio's huge tourism industry and the health of fish.

The plan would limit the amount of phosphorus and nitrogen that come mainly from farm fertilizers, manure and sewage.

Reducing the manure and fertilizer runoff from farms and the waste dumped by sewage treatment plants that contribute to algae blooms in lakes has become a priority for the Ohio Environmental Protection Agency.

The blooms turn the water into a pea soup color and produce toxins that have contributed to oxygen-deprived dead zones where fish can't survive. Those toxins also can sicken people and kill pets and foul drinking water.

Other inland lakes in Ohio, most notably Grand Lake St. Marys in western Ohio, have battled algae outbreaks in recent years.

The state's proposal would set specific limits for phosphorus and nitrogen in each Ohio stream, Ohio EPA Director Scott Nally told The Columbus Dispatch (http://bit.ly/1bqcmpu ).

Federal regulators are reviewing the plan.

Only two other states, Florida and Wisconsin, have limits for phosphorus and nitrogen in waterways.

Ohio's proposal is to take into account the phosphorus and nitrogen in the streams along with the amount of algae and aquatic wildlife.

State regulators think that some streams can still be considered healthy even if there are higher concentrations of nutrients, Nally said.

Ohio farmers have been encouraged to voluntarily cut down on the manure and fertilizer that runs off their fields and pollutes the lakes and rivers

The Ohio Farm Bureau Federation and other agriculture industry groups asked farmers this year to take proactive steps such as not using more fertilizer than needed before the government has a chance to impose restrictions.

The group said that it wants to know more about the state's proposal to limit pollution in streams and how it might affect farmers.

"It doesn't make a lot of sense to establish a (limit) so low that it's not attainable," said Larry Antosch, the farm bureau's environmental policy director.